package test;

public class demo01 {
    public static void main(String args[]) {
        StringBuffer a = new StringBuffer("A");
        StringBuffer b = new StringBuffer("B");
        operater(a,b);
        System.out.println(a+" "+b);// AB B
    }
    public static void operater(StringBuffer x, StringBuffer y) {
        x.append(y);
        y = x;
        System.out.println(x+" "+y);// AB AB
    }
}
